Dissertations / Theses on the topic 'Rhodococcus rhodochrous'
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Strachan, Philip. "Catechol 1,2-dioxygenase from Rhodococcus rhodochrous NCIMB 13259." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337527.
Full textHarris, Randall. "Degradation of dichloroalkanes by Rhodococcus rhodochrous and Pseudomonas oleovorans." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98965.
Full textAshraf, William. "The genetics and biochemistry of a propane-utilizing "Rhodococcus rhodochrous"." Thesis, University of Warwick, 1990. http://wrap.warwick.ac.uk/3991/.
Full textPaylor, Michael Mark. "Biotransformation of organosulfides with the bacterium Rhodococcus rhodochrous ATCC 19067." Thesis, University of Exeter, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245300.
Full textDadd, Michael Richard. "Chiral biotransformations of cylclic nitrile compounds." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365818.
Full textDrago, Gene K. "Studies Directed to the Optimization of Fermentation of Rhodococcus sp. DAP 96253 and Rhodococcus rhodochrous DAP 96622." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/biology_diss/24.
Full textMihdhir, Alaa. "The physiology, biochemistry and genetics of propane metabolism in Rhodococcus rhodochrous PNKB1." Thesis, University of Warwick, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387396.
Full textBui, Soi. "Characterisation of the RDX-degrading XplA/XplB redox system from Rhodococcus rhodochrous." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/characterisation-of-the-rdxdegrading-xplaxplb-redox-system-from-rhodococcus-rhodochrous(9355f6f0-62e8-4e07-ad16-786f00a957af).html.
Full textChorao, Charlène. "Etude du métabolisme de Rhodococcus rhodochrous lors de la photobiodégradation du 2-aminobenzothiazole." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2008. http://tel.archives-ouvertes.fr/tel-00731145.
Full textZhang, Jie. "Biofiltration of Acrylonitrile by Rhodococcus Rhodochrous DAP 96622 on a Trickling Bed Bioreactor." Digital Archive @ GSU, 2009. http://digitalarchive.gsu.edu/biology_diss/64.
Full textKomeda, Hidenobu. "Organization and Regulation of Genes Involved in Nitrile Metabolism in Rhodococcus rhodochrous J1." Kyoto University, 1996. http://hdl.handle.net/2433/160870.
Full textKyoto University (京都大学)
0048
新制・課程博士
博士(農学)
甲第6519号
農博第895号
新制||農||726(附属図書館)
学位論文||H8||N2948(農学部図書室)
UT51-96-K87
京都大学大学院農学研究科農芸化学専攻
(主査)教授 清水 昌, 教授 駒野 徹, 教授 加藤 暢夫
学位規則第4条第1項該当
Frederick, Joni. "Genetic characterization of Rhodococcus rhodochrous ATCC BAA-870 with emphasis on nitrile hydrolysing enzymes." Doctoral thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/4262.
Full textIncludes bibliographical references.
Rhodococcus rhodochrous ATCC BAA-870 (BAA-870) had previously been isolated on selective media for enrichment of nitrile hydrolysing bacteria. The organism was found to have a wide substrate range, with activity against aliphatics, aromatics, and aryl aliphatics, and enantioselectivity towards beta substituted nitriles and beta amino nitriles, compounds that have potential applications in the pharmaceutical industry. This makes R. rhodochrous ATCC BAA-870 potentially a versatile biocatalyst for the synthesis of a broad range of compounds with amide and carboxylic acid groups that can be derived from structurally related nitrile precursors. The selectivity of biocatalysts allows for high product yields and better atom economy than nonselective chemical methods of performing this reaction, such as acid or base hydrolysis. In order to apply BAA-870 as a nitrile biocatalyst and to mine the organism for biotechnological uses, the genome was sequenced using Solexa technology and an Illumina Genome Analyzer. The Solexa sequencing output data was analysed using the Solexa Data Analysis Pipeline and a total of 5,643,967 reads, 36-bp in length, were obtained providing 4,273,289 unique sequences. The genome sequence data was assembled using the software Edena, Velvet, and Staden. The best assembly data set was then annotated automatically using dCAS and BASys. Further matepaired sequencing, contracted to the company BaseClear® BV in Leiden, the Netherlands, was performed in order to improve the completeness of the data. The scaffolded Illumina and mate-paired sequences were further assembled and annotated using BASys. BAA-870 has a GC content of 65% and contains 6997 predicted protein-coding sequences (CDS). Of this, 54% encodes previously identified proteins of unknown function. The completed 5.83 Mb genome (with a sequencing coverage of 135 X) was submitted to the NCBI Genome data bank with accession number PRJNA78009. The genome sequence of R. rhodochrous ATCC BAA-870 is the seventh rhodococcal genome to be submitted to the NCBI and the first R. rhodochrous subtype to be sequenced. An analysis of the genome for nitrile
Thuku, Robert Ndoria. "The structure of the nitrilase from Rhodococcus Rhodochrous J1: homology modeling and three-dimensional reconstruction." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3225_1188474860.
Full textThe nitrilases are an important class of industrial enzymes that are found in all phyla. These enzymes are expressed widely in prokaryotes and eukaryotes. Nitrilases convert nitriles to corresponding acids and ammonia. They are used in industry as biocatalysts because of their specificity and enantioselectivity. These enzymes belong to the nitrilase superfamily in which members share a common &alpha
&beta
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structural fold and a unique cys, glu,lys catalytic triad with divergent N- and C-terminals.
There are four atomic structures of distant homologues in the superfamily, namely 1ems, 1erz, 1f89 and 1j31. All structures have two-fold symmetry which conserves the &alpha
&beta
&beta
&alpha
-&alpha
&beta
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fold across the dimer interface known as the A surface. The construction of a 3D model based on the solved structures revealed the enzyme has two significant insertions in its sequence relative to the solved structures, which possibly correspond to the C surface. In addition there are intermolecular interactions in a region of a conserved helix, called the D surface. These surfaces contribute additional interactions responsible for spiral formation and are absent in the atomic resolution homologues.
The recombinant enzyme from R.rhodochrous J1 was expressed in E. coli BL21 cells and eluted by gel filtration chromatography as an active 480 kDa oligomer and an inactive 80 kDa dimer in the absence of benzonitrile. This contradicts previous observations, which reported the native enzyme exists as an inactive dimer and elutes as a decamer in the presence benzonitrile. Reducing SDS-PAGE showed a subunit atomic mass of ~40 kDa. EM and image analysis revealed single particles of various shapes and sizes, including c-shaped particles, which could not form spirals due to steric hindrances in its C terminal.
Chromatographic re-elution of an active fraction of 1-month old J1 nitrilase enabled us to identify an active form with a mass greater than 1.5 MDa. Reducing SDS-PAGE, N-terminal sequencing and mass spectroscopy showed the molecular weight was ~36.5 kDa as result of specific proteolysis in its C terminal. EM revealed the enzyme forms regular long fibres. Micrographs (109) were recorded on film using a JEOL 1200EXII operating at 120 kV at 50K magnification. Two independent 3D reconstructions were generated using the IHRSR algorithm executed in SPIDER. These converged to the same structure and the resolution using the FSC 0.5 criterion was 1.7 nm.
The helix structure has a diameter of 13nm with ~5 dimers per turn in a pitch of 77.23 Å
. Homology modeling and subsequent fitting into the EM map has revealed the helix is built primarily from dimers, which interact via the C and D surfaces. The residues, which potentially interact across the D surface, have been identified and these confer stability to the helix. The conservation of the insertions and the possibility of salt bridge formation on the D surface suggest that spiral formation is common among microbial nitrilases. Furthermore, the presence of the C terminal domain in J1 nitrilase creates a steric hindrance that prevents spiral formation. When this is lost &ndash
either by specific proteolysis or autolysis - an active helix is formed.
Alves, Marileide Moraes. "Concep??o e estudo de um biofiltro para tratamento de compostos org?nicos vol?teis COVs." Universidade Federal do Rio Grande do Norte, 2005. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15940.
Full textCoordena??o de Aperfei?oamento de Pessoal de N?vel Superior
In the last decade, biological purification of gaseous waste has become an important alternative to many conventional methods of exhaust air treatment. More recently, biofiltration has proved to be an effective and inexpensive method for the treatment of air contaminated with volatile organic compounds (VOCs). A biofilter consists in a reactor packed with a porous solid bed material, where the microorganisms are fixed. During the biofiltration process, polluted air is transported through the biofilter medium where the contaminant is degraded. Within the biofilm, the pollutants in the waste gases are energy and carbon sources for microbial metabolism and are transformed into CO2, water and biomass. The bed material should be characterized by satisfactory mechanical and physical properties as structure, void fraction, specific area and flow resistance. The aim of this research was the biofilter construction and study of the biological degradation of ethanol and toluene, as well as the modeling of the process. Luffa cylindrica is a brazilian fiber that was used as the filtering material of the present work. The parameters and conditions studied were: composition of nutrients solution; effect of microflorae strains, namely Pseudomanas putida and Rhodococcus rhodochrous; waste gas composition; air flow rate; and inlet load of VOCs. The biofilter operated in diffusion regime and the best results for remotion capacity were obtained when a microorganisms consortion of Pseudomanas putida and Rhodococcus rhodochrous,were used, with a gas flow rate of 1 m3.h-1 and molar ratio nitrogene/phosphore N/P=2 in the nutrients solution. The maximum remotion capacity for ethanol was around 90 g.m-3.h-1 and 50 g.m-3.h-1 to toluene. It was proved that toluene has inhibitory effect on the ethanol remotion When the two VOCs were present in the same waste gas, there was a decrease of 40% in ethanol remotion capacity. Luffa cylindrica does not present considerable pressure drop. Ottengraf and van Lith models were used to represent the results obtained for ethanol and toluene, respectively. The application of the transient model indicated a satisfactory approximation between the experimental results obtained for ethanol and toluene vapors biofiltration and the ones predicted it
Na ultima d?cada, a purifica??o biol?gica de rejeitos gasosos tem sido uma importante alternativa em detrimento dos m?todos convencionais de tratamento. Mais recentemente, a biofiltra??o tem se mostrado um m?todo efetivo e de baixo custo para tratamento de ar contaminado com compostos org?nicos vol?teis (COVs). O biofiltro ? um reator que possui um leito filtrante constitu?do por um material poroso, onde est?o fixados os microrganismos. Durante o processo de biofiltra??o, o ar polu?do ? transportado ao longo do leito onde o contaminante ? degradado. No biofilme, os poluentes presentes no efluente gasoso ser?o a fonte de carbono e energia para os microrganismos e ap?s serem metabolizados ser?o transformados em CO2, ?gua e biomassa. O leito filtrante deve ser caracterizado por propriedades f?sicas e mec?nicas como estrutura, fra??o de vazios, ?rea especifica e resist?ncia ao fluxo gasoso. O principal objetivo deste trabalho de pesquisa foi a constru??o de um biofiltro e o estudo da degrada??o do etanol e tolueno, bem como a modelagem do processo. Luffa cylindrica ? uma fibra bastante encontrada no nordeste do Brasil e foi utilizada no presente trabalho como leito filtrante. Os par?metros e condi??es estudos foram: composi??o da solu??o nutriente; efeito da esp?cie de microrganismos, denominadas Pseudomanas putida e Rhodococcus rhodochrous; composi??o do efluente gasoso; taxa de fluxo gasoso e carga de entrada do COV. O biofiltro operou em regime difusional, sendo os melhores resultados para a capacidade de remo??o foram obtidos quando utilizado o cons?rcio de microrganismos de Pseudomanas putida e de Rhodococcus rhodochrous, com uma vaz?o volum?trica de ar de 1 m3.h-1 e raz?o molar nitrog?nio/fosforo N/P=2 na solu??o nutriente. A m?xima capacidade de elimina??o foi de 90 g.m-3.h-1 para o etanol e 50 g.m-3.h-1 para o tolueno. Constatou-se que o tolueno tem efeito inibit?rio sobre a degrada??o do etanol, quando os dois VOCs est?o presentes no mesmo efluente, houve uma queda de 40% na remo??o do etanol. A Luffa cylindrica n?o apresentou grandes valores de perda de carga. Os modelos de Ottengraf e van Lith representaram bem os resultados obtidos para o etanol e tolueno, respectivamente. A aplica??o do modelo transiente evidenciou uma aproxima??o satisfat?ria entre os resultados experimentais obtidos para a biofiltra??o de vapores de etanol e tolueno e aqueles previstos pelo referido modelo
WANG, CUI. "Enhanced Activity And Stability Of Enzymes Associated With Delayed Fruit Ripening In Rhodococcus rhodochrous DAP 96253." Digital Archive @ GSU, 2013. http://digitalarchive.gsu.edu/biology_diss/131.
Full textDu, Fengkun. "Comparison of Nitrile Hydratases in Rhodococcus Rhodochrous DAP 96253 and DAP 96622 Growing on Inducing and Non-Inducing Media." Digital Archive @ GSU, 2013. http://digitalarchive.gsu.edu/biology_diss/130.
Full textRodrigues, Edmo Montes. "Biodiversidade microbiana da Ilha da Trindade, prospecção genética e aplicações biotecnológicas utilizando micro-organismos autóctones." Universidade Federal de Viçosa, 2016. http://www.locus.ufv.br/handle/123456789/10020.
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Fundação de Amparo à Pesquisa do Estado de Minas Gerais
Esse estudo é iniciado com uma revisão bibliográfica em que aborda a biorremediação de hidrocarbonetos pesados e hidrocarbonetos aromáticos policíclicos (PAHs). Na revisão, são explorados aspectos que incluem a obtenção de micro- organismos com capacidade de degradar hidrocarbonetos, vias metabólicas de biodegradação, as consequências ambientais da contaminação e por fim aborda novos estudos que utilizam estratégias e novas tecnologias de biorremediação possíveis em ambientes aquáticos e solos. A parte experimental de nosso estudo segue a mesma linha de pesquisa desenvolvida durante o mestrado. De maneira preventiva, busca-se avaliar e desenvolver metodologias para biorremediar as adjacências da Ilha da Trindade, ambiente pristino e de valor ecológico, caso ocorram acidentes envolvendo o derramamento de hidrocarbonetos. Inicialmente, objetivamos avaliar o genoma dos isolados bacterianos autóctones da comunidade microbiana existente nas águas marinhas que circundam a Ilha da Trindade, Rhodococcus rhodochrous TRN7 e Nocardia farcinica TRH1, isolados durante o trabalho de mestrado como sendo capazes de degradar uma grande variedade de hidrocarbonetos de petróleo. Nosso objetivo também foi avaliar a estrutura da comunidade microbiana e o catabolismo de fenantreno após contaminação de microcosmos contendo água coletada na mesma região e utilizar micro-organismos autóctones como estratégia de bioaumentação. Por fim, objetivou-se desenvolver um produto biotecnológico baseado em emulsões duplas W/O/W fertilizadas, capaz de promover a bioestimulação sem a perda instantânea de nutrientes em águas oceânicas oligotróficas contaminadas por compostos orgânicos hidrofóbicos. Os genomas de R. rhodochrous TRN7 e N. farcinica TRH1 possuem genes de degradação de compostos alifáticos e aromáticos, sendo que 17 genes envolvidos com a biossíntese de antibióticos foram anotados com o genoma de R. rhodochrous TRN7, enquanto que no genoma de N. farcinica TRH1 foram identificados genes relacionados à degradação de caprolactam, precurssor do nylon, e do pesticida atrazina, o que torna ambos os isolados candidatos a serem empregados tanto em estratégias de bioaumentação quanto em outras áreas biotecnológicas. Após a contaminação de microcosmos com hidrocarbonetos, a comunidade microbiana da água litorânea da Ilha da Trindade passa a ser dominada por Gammaproteobacteria, grupo que compõe mais de 72% das sequências analisadas, enquanto que no tratamento controle houve predomínio de Proteobacteria (95% das sequências). Destaca-se a abundância de representantes do gênero Alteromonas, presentes em todos os tratamentos contaminados, com maior valor de abundância (66% das sequências) no tratamento contendo apenas fenantreno como contaminante. Decorridos 30 dias da contaminação, os valores de diversidade foram reduzidos, havendo domínio de grupos bacterianos reconhecidos pela presença de membros com atividade hidrocarbonoclástica. A capacidade de mineralização de fenantreno pela microbiota autóctone da Ilha da Trindade é reduzida quando outros PAHs e hidrocarbonetos de alto peso molecular estão presentes no ambiente. Em relação às emulsões produzidas, nossos resultados mostraram que elas podem ser utilizadas com o propósito de liberação gradual de nutrientes na fase aquosa dispersa. A emulsão é composta por gotículas que variam em um amplo espectro de tamanho que se desestabilizam temporalmente, resultando na liberação da inorgânicos. Quando utilizadas em hidrocarbonoclásticas, fase aquosa conjunto em microcosmos interna, ou contendo não, água contendo nutrientes com bactérias litorânea da Ilha da Trindade contaminada com petróleo, as emulsões W/O/W fertilizadas proporcionaram aumentos significativos da atividade microbiana. Como conclusões, nosso trabalho mostrou que a contaminação por hidrocarbonetos resulta na perda de diversidade microbiana da comunidade microbiana da água litorânea da Ilha da Trindade, e que um ambiente considerado pristino possui microbiota capaz de degradar hidrocarbonetos. Por fim, conclui-se que emulsões duplas W/O/W fertilizadas são uma alternativa para proporcionar aumento significativo na atividade catabólica de hidrocarbonetos em ambientes marinhos oligotróficos.
This study starts with a literature review approach in heavy hydrocarbon bioremediation and polycyclic aromatic hydrocarbons (PAHs). In the review are explored aspects from obtaining microorganisms capable of degrading hydrocarbons, metabolic biodegradation pathways, environmental consequences of contamination and finally discusses new studies using new strategies and bioremediation technologies in water and soil environments. The experimental part of our study follows the same research line developed during the Masters. Preventively, seeks to assess and develop bioremediation methodologies for Trindade Island shoreline, pristine environment with ecological value, should they occur involving the oil spill. Initially we aimed to evaluate the genome of indigenous bacterial isolates Rhodococcus rhodochrous TRN7 and Nocardia farcinica TRH1, isolated during master’s work as being capable of degrading a wide range of petroleum hydrocarbons. Our aim was also to evaluate the microbial community structure and metabolism of PAHs after contamination in microcosms and use indigenous microorganisms as bioaugmentation strategy. Finally, it aimed to develop a biotechnolocal product based on double emulsion W/O/W fertilized able to promote biostimulation without the instant loss of nutrients in oligotrophic oceanic waters contaminated with hydrophobic organic compounds. The genomes of R. rhodochrous TRN7 and N. farcinica TRH1 presents aliphatic and aromatic compounds degradation genes. Moreover, 17 genes involved in the biosynthesis of antibiotics were recorded in the genome of R. rhodochrous TRN7 while in the genome of N. farcinica TRH1 were identified genes related to the degradation of caprolactam, a nylon precursor, and the pesticide atrazine, which makes the isolates candidates to be used in both strategies bioaugmentation as for other biotechnological activity. After contamination by hydrocarbons, in microcosms, the microbial community of the coastal water from Trindade Island becomes dominated by Gammaproteobacteria, a group that makes up more than 72% of the analyzed sequences, while in the control treatment predominated Proteobacteria (95% of the sequences). Noteworthy is the abundance of representatives of the genus Alteromonas, present in all the contaminated treatments with highest abundance (66% of the sequences) in the treatment containing phenanthrene as only contaminant. After 30 days of contamination, diversity values were reduced, with domain of bacterial groups recognized by the presence of members with hydrocarbonoclastic activity. The phenanthrene mineralization capacity by the indigenous microbiota of the Trindade Island is reduced when other PAHs and high molecular weight hydrocarbons are present in the environment, however, does not cease to occur. With respect to emulsions produced, our results showed that they can be used for the purpose of slow release nutrients in the dispersed aqueous phase. The emulsion comprises droplets ranging in a wide range of size that destabilize temporally, resulting in the release of the internal aqueous phase, containing inorganic nutrients. When used together or not, hydrocarbonoclastic bacteria in microcosms containing coastal water from Trindade Island contaminated with oil, the fertilized W/O/W emulsion provided significant increases in microbial activity. In conclusion, our work has shown that hydrocarbons contamination results in the loss of microbial diversity in marine environments, in addition to state that as environment considered pristine has microbiota capable of degrading hydrocarbons and therefore it becomes viable the use of strategies as biostimulation and bioaugmentation employing indigenous bacterial isolates previously selected. Finally, it is concluded that fertilized W/O/W emulsions are an alternative to provide significant increase in catabolic activity hydrocarbons oligotrophic marine environments.
Teixeira, Liliana Patrícia dos Reis. "Production of sophorolipds with a branched hydrophobic tail." Master's thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15310.
Full textSophorolipids are a type of biosurfactants produced by several microorganisms, including the yeast Starmerella bombicola. They find application mainly due to their emulsifying activity and antimicrobial properties. Sophorolipids produced by Starmerella bombicola are composed by one sophorose molecule and a hydroxylated fatty acid of 16 or 18 carbon atoms. One or two acetylations can occur, one on each glucose, and a lactonization as well. Despite the interesting characteristics of classic sophorolipids produced by the referred yeast, there are indications that sophorolipids with branched a hydrophobic tail have higher activity at lower temperatures. These sophorolipids are produced by Rhodotorula bogoriensis, however the yields obtained with this yeast are low. By producing these sophorolipids in Starmerella bombicola, the yields obtained could be higher. Furthermore, the production of these novel sophorolipids will allow broadening of the biosurfactants applications. This thesis describes two approaches to produce sophorolipids with a branched hydrophobic tail: use of Guerbet alcohols as substrates for the Starmerella bombicola culture, and the introduction of genes that will take care of the in-chain hydroxylation of the sophorolipids. Guerbet alcohols are branched molecules, and are expected to be incorporated in the sophorolipids molecules. The genes to be used are from Elizabethkingia meningoseptica and Rhodococcus rhodochrous and encode for an oleate hydratase, an enzyme responsible for the conversion of oleic acid into 10-hydroxystearic acid.
Soforolípidos são um tipo de biosurfactantes produzidos por vários microorganismos, incluindo a levedura Starmerella bombicola. As suas principais aplicações devem-se à sua sua atividade emulsificante e propriedades antimicrobianas. Soforolípidos produzidos por Starmerella bombicola são compostos por uma molécula de soforose e um ácido gordo hidroxilado de 16 ou 18 átomos de carbono. Apesar das interessantes caraterísticas dos soforolípidos clássicos produzidos pela levedura referida, há indicações de que os soforolípidos com cauda hidrofóbica ramificada têm maior atividade a temperaturas mais elevadas. Estes soforolípidos são produzidos por Rhodotorula bogoriensis, no entanto o rendimento obtido por esta levedura é baixo. Ao produzir estes soforolípidos em Starmerella bombicola, o rendimento obtido poderá ser superior. A produção destes soforolípidos irá também permitir o alargamento das aplicações dos biosurfactantes. Esta tese descreve duas medidas para a produção de soforolípidos com cauda hidrofóbica ramificada: uso de álcoois de Guerbet como substrato para a cultura de Starmerella bombicola, e a introdução de genes que serão responsáveis pela hidroxilação no meio da cadeia hidrofóbica dos soforolípidos. Álcoois de Guerbet são moléculas ramificadas, sendo esperado a sua incorporação nas moléculas de soforolípidos. Os genes usados são provenientes de Elizabethkingia meningoseptica e Rhodococcus rhodochrous, e codificam para uma oleate hidratase, enzima responsável pela conversão do ácido oleico no ácido 10-hidroxistearico.
Costa, Vilma Ara?jo da. "Avalia??o da biodessulfuriza??o de 4-metildibenzotiofeno por Rhodococus rhodochrous (NRRL B-2149)." Universidade Federal do Rio Grande do Norte, 2011. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12966.
Full textCrude oil has between 0.04 up to 5% of sulphur, the higher the oil the higher the sulphur levels. Sulphur usually gives problems such as corrosion in refinery, and once burnt produces SO2 that goes to atmosphere. This work aim to investigate the capacity of Rhodococcus rhodochrous (NRRL B-2149) to metabolize the model compound 4-methyldibenzotiophene (4-MDBT), to remove the sulphur and transform it in 2-hydroxybiphenyl (2-HBF) and sulphite using the 4S pathway. Kynetic runs were carried out in shaker at 120 rpm and 32?C. Samples were taken every 12h to assay substrate consume as well as cells production using HPLC. Results showed that R. rhodochrous NRRL B-2149 can use the 4S pathway in order to remove sulphur without change the carbon chain of the molecule as well as that cells and 4-MDBT affects the product formation. The production of 2-hydroxybiphenyl has interest for industry once it is a potent biocide. However, evaluation is necessary in order to obtain better results compatible with industry needs
O petr?leo bruto convencional cont?m entre 0,04 a 5% de enxofre, e em geral ?leos mais densos apresentam teores mais elevados. Embora pequena, esta fra??o ? importante e sua presen?a torna-se indesej?vel, tanto por promover a corros?o do equipamento da refinaria, como porque parte dela persiste na composi??o dos derivados, que, ao serem queimados, liberam di?xido de enxofre (SO2) para a atmosfera. Este ? um dos principais poluentes atmosf?ricos, respons?vel pelas chuvas ?cidas. O presente trabalho teve como objetivo avaliar a capacidade da cepa Rhodococcus rhodochrous (NRRL B-2149) em metabolizar o composto modelo 4-metildibenzotiofeno (4-MDBT), remover-lhe o ?tomo de enxofre e convert?-lo em 2-hidr?xibifenil (2-HBF) e sulfito utilizando a via sulf?xido-sulfona-sulfonato-sulfato ( 4S ), sem reduzir significativamente seu poder calor?fico. Para essa avalia??o foi realizado um estudo cin?tico em incubador rotativo sob agita??o de 120 rpm e 32?C. As amostras foram retiradas em intervalos de 12 h para an?lise da concentra??o celular e consumo de substrato e quantificadas por cromatografia l?quida. Os resultados mostraram que a cepa de R. rhodochrous NRRL B-2149 ? capaz de utilizar a Via 4S para remover o enxofre do composto sem contudo, alterar sua cadeia carb?nica e que a concentra??o de c?lulas e de 4-MDBT interferem na forma??o do produto 2-HBF. A produ??o do 2-hidroxibifenil detectada neste estudo ? de grande relev?ncia j? que ele ? um biocida potente de interesse industrial. No entanto, avalia-se condi??es dos ensaios visando obter concentra??es vi?veis para amplia??o industrial
2020-01-01
Saqib, Muzna. "Evaluation of Induced Cells of Rhodococcus Rhodochrous to Inhibit Fungi." 2016. http://scholarworks.gsu.edu/biology_hontheses/9.
Full textEMMER, Jiří. "Structural studies of the haloalkane dehalogenase mutant (DhaA12) from \kur{Rhodococcus rhodochrous}." Master's thesis, 2007. http://www.nusl.cz/ntk/nusl-46966.
Full textFrederick, Joni. "Characterisation of the nitrile biocatalytic activity of rhodococcus Rhodochrous ATCC BAA-870." Thesis, 2007. http://hdl.handle.net/10539/2016.
Full textA versatile nitrile-degrading bacterium was isolated through enrichment culturing of soil samples from Johannesburg, South Africa. It was identified as Rhodococcus rhodochrous and submitted to the ATCC culture collection as strain BAA-870. This organism was determined to be a potential biocatalyst in that it contains a two enzyme system with strong nitrile-converting activity comprising nitrile hydratase and amidase. The development of a suitable assay for measuring the activity of the enzymes of interest was explored. A pHsensitive indicator-based assay was found to be suitable only for colorimetrically identifying highly concentrated enzymes with acid-forming activity. An ophthaldialdehyde- based fluorimetric assay was found to be applicable to conversions of select compounds, but the assay could not be used to measure the activity of Rhodoccocus rhodochrous ATCC BAA-870. High performance liquid chromatography was the most suitable method for reliable and quantitative measurement of nitrile hydrolysis, and is applicable to monitoring activities of whole-cell and cell-free extracts. Initial analysis of six compounds, benzonitrile, benzamide, benzoic acid, hydrocinnamonitrile, 3-hydroxy-3- phenylpropionitrile and 3-hydroxy-3-phenylpropionic acid, was performed by HPLC to measure linearly the average retention area, amount and absorbance of the compounds up to 10 mM concentrations. The conversion of the substrates benzonitrile, benzamide and 3- hydroxy-3-phenylpropionitrile were further analysed with respect to time and enzyme concentration. Conversion of benzonitrile to benzamide by the nitrile hydratase was rapid and could be measured in 10 minutes. Conversion of benzamide to benzoic acid by the amidase was considered the rate-limiting step and could be followed for 90 minutes of the reaction at the concentrations tested. Conversion of 3-hydroxy-3-phenylpropionitrile was linearly measured over 20 minutes. Mass spectral analysis was used to confirm, at a structural level, relatively less volatile reactant compounds with a higher thermal stability, including benzamide, 3-hydroxy-3-phenylpropionitrile and 3-hydroxy-3-phenylpropionic acid. Protein concentration studies indicated that activity against benzonitrile was probably due to a nitrile hydratase with potent activity rather than a concentrated enzyme, since formation of benzamide from benzonitrile showed first order reaction kinetics at protein concentrations less than 0.2 mg/ml. Formation of benzoic acid from benzamide was linear up to 1.3 mg total protein and product formation from 3-hydroxy-3-phenylpropionitrile was linear up to 1.4 mg total protein. Overlapping activities against benzonitrile and 3- hydroxy-3-phenylpropionitrile indicate that the nitrile hydratase has differing substrate specificity for the two compounds, with higher activity toward the small aromatic mononitrile, benzonitrile, than the arylaliphatic b-hydroxy nitrile, 3-hydroxy-3- phenylpropionitrile. The nitrile-converting activity of Rhodococcus rhodochrous ATCC BAA-870 would be suitable for biocatalysis as the conversions take place under a wide pH range, require low concentrations of enzyme and reactions are fast. Separation of nitrileconverting activities in Rhodococcus rhodochrous ATCC BAA-870 was undertaken using various chromatography methods to establish a simple, one-step protocol for biocatalytic enzyme preparations. HPLC was not suited to assaying nitrile-converting activity in chromatofocusing fractions, and chromatofocusing Ampholyte buffers were found to interfere with activity measurements. Gel exclusion chromatography of the soluble protein extract from Rhodococcus rhodochrous ATCC BAA-870 indicated the enzyme/s responsible for nitrile hydratase activity are high molecular weight proteins ranging from 40 to 700 kDa in size, while the amidase native enzyme is proposed to be roughly 17 to 25 kDa. SDS-PAGE analysis of gel exclusion and ion exchange chromatography fractions indicated nitrile converting activity in Rhodococcus rhodochrous ATCC BAA-870 is likely due to multimer-forming enzymes made up of 84, 56, 48 and 21 kDa subunits. It is postulated that nitrile hydratase is made up of ab and a2b2 tetramers that may form larger enzyme aggregates. Ion exchange chromatography was used to separate nitrile hydratase with high activity against benzonitrile and 3-hydroxy-3-phenylpropionitrile from amidase activity, and showed that an additional, substrate specific nitrile hydratase may exist in the organism.
Mashweu, Adelaide. "Substrate evaluation of the nitrile degrading enzymes from Rhodococcus rhodochrous ATCC BAA 870." Thesis, 2020. https://hdl.handle.net/10539/31394.
Full textThe focus of this research was the nitrile degrading enzymes nitrile hydratases (NHase) and whole cell nitrilases. NHases and whole cell nitrilases have not been as extensively applied in industry as they could be due to a number of reasons, including missing information relating to their substrate scope. Therefore, this research focussed on exploring the activity of both NHase and whole cell nitrilase towards a number of nitrile compounds. The Groebke-Blackburn-Bienayméreaction (GBB) and Suzuki-Miyaura coupling reaction were employed to synthesize aromatic nitrile-bearing imidazo[1,2-a]pyridine and biaryl compounds respectively. These compounds were of varying sizes and the nitrile group was subjected to different electronic effects through incorporation of different substituents. Vinyl nitrile compounds were synthesized using the Morita-Baylis Hillman reaction (MBH), while simple nitrile compounds were purchased. The synthesized nitrile-bearing imidazo[1,2-a]pyridine compounds were subjected to both NHase and whole cell nitrilase, however, these enzymes were inactive towards these compounds. NHase showed activity towards the biaryl compounds, however, there was complete loss of activity when the biaryl compounds had a 3,4-dimethoxy group as a substituent irrespective of its position relative to the nitrile group. There was also no activity when the 3,4-difluorophenyl group was in the ortho-position relative to the nitrile functional group. NHase also showed activity towards the MBH compounds, however, the rate of hydrolysis was slow in comparison with that of the biaryl compounds. NHase was inactive towards one MBH compound bearing a trimethoxyphenylgroup as a substituent. Whole cell Nitrilase had no activity towards the MBH compounds and extending the time for hydrolysis resulted in no significant changes. NHase demonstrated excellent activity towards the simple commercially available nitrile compounds, however, the rate of hydrolysis towards nitrile compounds bearing electron-withdrawing substituents was faster in comparison with those bearing electron-donating substituents
CK2021
Nunes, Guilherme Duarte Camarinha. "Effect of growth conditions on the activity of Michael hydratase from Rhodococcus rhodochrous ATCC 17895." Master's thesis, 2017. http://hdl.handle.net/10362/25464.
Full textWang, Cui. "Enhanced Activity And Stability Of Enzymes Associated With Delayed Fruit Ripening In Rhodococcus rhodochrous DAP 96253." 2013. http://scholarworks.gsu.edu/biology_diss/131.
Full textGovindjee, Varsha Parshotam. "Biocatalytic potetial of degrading enzyme systems belonging to the genus rhodococcus rhodochrous, new approaches towards green chemistry." Thesis, 2018. https://hdl.handle.net/10539/25927.
Full textIn an attempt to find more efficient and "greener" catalytic processes towards the synthesis of advanced pharmaceutical intermediates, three bacterial strains, namely Rhodococcus rhodochrous ATCC BAA-870, R. rhodochrous A29 and Pimelobacter simplex A99, were evaluated as nitrile hydrolysing biocatalysts. R. rhodochrous ATCC BAA-870 showed constitutive expression of a low-molecular weight cobalt containing nitrile hydratase and a highly enantioselective amidase enzyme that were involved in the kinetic resolution of 3-hydroxy-3-aryloxybutanenitrile and 3-hydroxy-3-arylpropanenitrile. The (R)-3- hydroxy-3-aryloxybutanamide and (S)-3-hydroxy-3-arylpropanamide intermediates were both accumulated with excellent enantioselectivity (>99% ee). Interestingly, the same cells demonstrated enantioselective resolution of β-substituted aminonitriles to amides through a moderately selective nitrile hydratase enzyme when adjusted to a higher pH. With the substrates 3-amino-3-(4-methoxyphenyl)propanenitrile, and 3-amino-3-p-tolylpropanenitrile an enantiomeric purity of the residual nitrile (85% ee and 21% ee respectively) was achieved; while the resultant amide was obtained with 62% ee (3-amino-3-(4-methoxyphenyl)propanamide) and 48% ee (3-amino-3-p-tolylpropanenitrile) respectively. Induction studies demonstrated that both nitrile hydratase and amidase expression in strains A29 and A99 were inducible, with transient expression observed when cultured in the presence of benzonitrile. Furthermore, in a noteworthy discovery, studies on strains ATCC BAA-870, A29 and A99 revealed that the incorporation of 0.5% (v/v) dimethylformamide during cultivation induced nitrilase gene expression. This was evident by the appearance of a new, dominant 40 kDa protein band observed by SDS-PAGE analysis, and confirmed by LCMS-MS sequencing (showing high similarity to Uniprot Q03217). The induced nitrilase in strains A29 and A99 was inhibited by the nitrilase inhibitors benzylamine (61.37% and 79.49%) and benzaldehyde (88.45% and 87.49%) respectively. ATCC BAA-870 cells were however unaffected due to the presence of the alternative nitrile hydratase and amidase system facilitating nitrile hydrolysis. The induced nitrilases converted 3-cyanopyridine to nicotinic acid, and showed excellent enantioselectivity towards 3-amino-3-phenylpropanenitrile (>99% ee), and moderate enantioselectivity towards 3-amino-3-(4-methoxyphenyl)propanenitrile (40% ee). Therefore, Rhodococcal species are capable of expressing various nitrile hydrolysing enzymes that are enantioselective towards classes of beta-substituted nitrile compounds representative of diverse pharmaceuticals such as beta blockers, statins and peptidomimetics. The activity profile of these versatile microbial biocatalyst can be tailored through induction to yield single enantiomer nitriles, carboxamides or carboxyacids.
MT 2018
Jiang, Wenxin. "The Preliminary Study on the Role of 1-Hexene Monooxygenase in Delayed Fruit Ripening by Rhodococcus rhodochrous DAP 96253." 2016. http://scholarworks.gsu.edu/biology_diss/171.
Full textBarlament, Courtney. "Process Improvements to Fed-batch Fermentation of Rhodococcus rhodochrous DAP 96253 for the Production of a Practical Fungal Antagonistic Catalyst." 2016. http://scholarworks.gsu.edu/biology_diss/170.
Full textSTSIAPANAVA, Alena. "Strukturní a funkční studie vybraných mutantů haloalkan dehalogenasy DhaA." Doctoral thesis, 2010. http://www.nusl.cz/ntk/nusl-80498.
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